Patent GB-436095-A (GB)
Title: Process for the manufacture of azodyestuffs
IPC: C09B43/40
Filed: 1934-04-04
Abstract: Azo dyes and soluble copper compounds thereof. --Azo dyestuffs are obtained by condensation of a mono- or poly-azo dyestuff containing at least once the grouping <FORM:0436095/IV/1> (in which R1 and R2 are residues of the benzene or naphthalene series, the hydroxy group is in o-position to the azo bridge and the halogen atom, Hal, is in o- or peri-position to the azo bridge) with ammonia, amines, alcoholates, phenolates, sulphites or sulphinic acid salts, in presence of a copper compound.  An acid-binding agent and/or a nitrogenous base, e.g. pyridine, may advantageously be present.  The products are in some cases free from copper and in other cases are the copper complex compounds from which the copper may be removed by treatment with acids, alkali sulphides or alkali cyanides.  The following examples are specified: (1) The dyestuff 2 : 4 - dichloraniline - 6 - sulphonic acid --> b -naphthol is heated with copper acetate in ethyl alcohol to 78 DEG  C., potassium hydroxide is added and the whole boiled for 1 hour; the product is the copper complex compound which on treatment with sodium sulphide in aqueous solution is converted into the copper-free dyestuff giving orange dyeings on wool.  (2) The dyestuff 2-chloraniline --> b -naphthol is boiled with copper acetate in alcohol, potassium hydroxide is added and boiling is continued for 3 hours; the product is identical with the dyestuff 2-ethoxyaniline --> b -naphthol.  (3) The dyestuff 8-chloro-1-naphthylamine --> b -naphthol is treated as in (2).  (4) The dyestuff 2-chloraniline-5-sulphonic acid --> b -naphthol is heated at 95 DEG  C. in an aqueous solution containing copper sulphate, Seignette salt and piperidine, sodium hydroxide solution is added during 1 hour and heating is continued for a further 1 hour; the copper-free dyestuff gives red dyeings on wool.  (5) The dyestuff 2-chloraniline-5-sulphonic acid --> b -naphthol is heated for 2 hours at 85 DEG  C. with b -hydroxyethylamine and the copper complex compound of the dyestuff 2-aminophenol-4-sulphonic acid --> b -naphthol; the product is an aminooxy azo dyestuff giving red dyeings on wool. (6) The dyestuff 2-chloraniline-5-sulphonic acid --> b -naphthol is boiled for 2 hours in an aqueous solution containing copper sulphate, sodium carbonate, pyridine and aniline and the mixture is acidified with acetic acid.  (7) The dyestuff 3-amino-4-chlorotoluene --> 2 : 5 : 7-naphtholdisulphonic acid is heated to 90 DEG  C. with an aqueous solution containing copper sulphate and sodium carbonate, sodium sulphite is added and the mixture is stirred for 3 hours; the diazo component may be replaced by 2-amino-3-chlorotoluene or 2-chloraniline and the coupling component by 2 : 6-naphtholsulphonic acid, 2 : 3 : 6-naphtholdisulphonic acid or 2 : 8 : 6-aminonaphtholsulphonic acid or an N-acyl derivative thereof.  (8) The dyestuff 2 : 4 - dichloraniline - 6 - sulphonic acid --> b -naphthol is heated for 1 hour at 95--100 DEG  C. with an aqueous solution containing copper sulphate, sodium carbonate and sodium sulphite; the product dyes wool golden yellow; the diazo component may be replaced by 2-chloraniline-5-sulphonic acid or 2 : 5-dichloraniline-4-sulphonic acid and the coupling component by an acylaminonaphthol.  (9) The dyestuff 1-chloro-2-naphthylamine-6-sulphonic acid --> 2 : 7-naphtholsulphonic acid is heated for 1 hour at 85--90 DEG  C. with an aqueous solution containing copper sulphate, sodium carbonate and sodium sulphite; the product dyes wool red.  Specification 388,332 is referred to.  2 : 4 - Dichloraniline - 6 - sulphonic acid is obtained by sulphonating 2 : 4-dichloraniline (1 mol.) with chlorosulphonic acid (1 mol.) in tetrachlorethane.